U.S. patent number 4,950,003 [Application Number 07/373,563] was granted by the patent office on 1990-08-21 for luggage cart.
Invention is credited to Gilbert J. Holtz.
United States Patent |
4,950,003 |
Holtz |
August 21, 1990 |
Luggage cart
Abstract
Improvements for slidably mounting a size-adjustable luggage
cart handle inverter U-shape in a lower U-shape, consisting of each
leg of the upper U-shape being disposed through a hole in a cap
covering the opening of the lower U-shape and having an integrally
molded hub with a threaded bore to thereby increase the number of
teeth threadably engaging the threaded member which bears against
the upper U-shape in any selected position of its sliding movement,
which determines the size of the handle, and thus obviate
thread-stripping, wobble and other such defects.
Inventors: |
Holtz; Gilbert J. (Yonkers,
NY) |
Family
ID: |
23472929 |
Appl.
No.: |
07/373,563 |
Filed: |
June 30, 1989 |
Current U.S.
Class: |
280/655;
280/47.315; 403/362 |
Current CPC
Class: |
B62B
1/125 (20130101); B62B 2202/24 (20130101); Y10T
403/7041 (20150115) |
Current International
Class: |
B62B
1/00 (20060101); B62B 1/12 (20060101); B62B
001/12 () |
Field of
Search: |
;280/638,35,639,655,655.1,47.18,47.315,47.371
;403/362,377,378,379 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Marmor; Charles A.
Assistant Examiner: Camby; Richard
Claims
What is claimed is:
1. Improvements for a luggage cart of the type having a
size-adjustable handle comprised of a telescoped together
cooperating pair of a first lower hollow tubular handle member with
an upper opening therein in which is slidably disposed a second
upper tubular handle member wherein the extent of the extension of
said second handle member beyond said first handle member upper
opening establishes the size of said handle of said luggage cart,
said second upper tubular member having first and second flared
ends, said first lower hollow tubular handle member having a first
and second ends having a crimped portions therein, said crimps
retaining said flared ends of said second tubular member within
said first lower hollow tubular member, a hollow cap disposed in
covering relation over said first handle member upper opening
having a central opening in aligned relation to said upper opening
and a cylindrical wall in encircling relation about the upper end
of said first handle member and extending in covering relation over
said crimps therein, said central opening of said cap being
slightly undersized with respect to the upper opening of said first
lower handle member, to thereby provide an optimum sliding
clearance for the size-adjusting sliding movement of said second
upper handle member, a laterally extending hub embodied in said cap
wall oriented transverse to the sliding direction of said second
handle member, said hub having a threaded opening therethrough
opening at its inner end into said hollow interior of said first
handle member so as to provide access to said second handle member
slidably disposed therein, and a threaded member adjustably
threadably disposed in said hub threaded opening for engaging said
second handle member incident to holding said second handle member
in a selected sliding position of movement, whereby said size of
said laterally extending hub is selected to provide a
correspondingly sized said threaded opening in said hub to provide
an optimum number of threadably interengaged teeth of said threaded
hub opening and said threaded member to obviate inadvertent
disengagement of said threaded member from said second handle
member during use of said luggage cart.
Description
The present invention relates to improvements for luggage carts of
the type used by travelers in airports or the like, and more
particularly, to a size-adjustable handle in which the threads do
not strip or other malfunctions occur in the threadably engaged
components which provide the selected handle size that is used
during use of the cart.
EXAMPLES OF THE PRIOR ART
In U.S. Pat. No. 4,261,447 issued to Arias et al., on Apr. 14,
1981, the position of movement of an upper handle member relative
to a lower handle member of a luggage art which, of course,
establishes the overall size of the handle, is prevented from
inadvertently changing by projecting a holding pin through one of
spaced openings in the legs of the upper handle member. The
available handle sizes, however, are limited to the number of
pin-receiving openings that are provided.
The available handle sizes are readily increased by having an inner
end of a threadable member bear against the surface, rather than
project into, the movable handle member, but the firmness of the
bearing contact often fails to prevent inadvertent changes in the
handle size during pushing or pulling of the cart with a heavy load
thereon.
The patent issued to Evans, et al., Pat. No. 2,578,409 on Mar. 30,
1950 is noted, even though related to a golf cart rather than a
luggage cart, for illustrating in FIG. 10 use of a nut 19 with a
hub having a threaded throughbore 20 for a handle size-adjusting
screw 21. The additional threads of the Evans, et al. threaded hub
throughbore contributes to the firmness at which bearing contact
can be made against the sliding handle member, but the welding
attachment of nut 19 to the lower handle member is an undersirable
manufacturing requirement.
In contract to the aforesaid, it is an object of the present
invention to provide an optimum number of interengaging teeth in
threadably engaged handle size-establishing components, but without
complicating the construction of the luggage cart. It is an
additional object to also assist in achieving smooth telescoping
movement of the movable upper handle member relative to the
stationary lower handle member.
In accordance with the present invention, the upper openings of the
U-shaped lower handle member are capped, and in each cap a traverse
integrally molded hub has a threaded throughbore to advantageously
increase the available teeth for engagement with the locking screw
to thereby obviate thread stripping and due to any other causes,
any inadvertent disengagement of the established bearing contact
that is made against the movable upper handle member. The cap
opening in alignment with the upper opening of the lower handle
member into which the upper handle member is slidably disposed, is
sized to allow sliding movement of the upper handle member but at
an optimum minimum sliding clearance, so that wobble is
significantly reduced. The construction material of the cap is also
preferably hard rubber or plastic, to assure smoothness in the
movement that occurs through the opening of the cap.
The description of the invention which follows, together with the
accompanying drawings should not be construed as limiting the
invention to the example shown and described because those skilled
in the art to which this invention appertains will be able to
devise other forms thereof within the ambit of the appended
claims.
FIG. 1 is a perspective view of a luggage cart in its folded
condition ready for transport or storage in which the handle
thereof is fully retracted into an optimum minimum size;
FIG. 2 is a similar view, but illustrating the cart in its unfolded
condition ready for use in which the handle in only partially
retracted to thereby correspondingly increase the size of the
handle; and
FIG. 3 is a sectional view of the handle locking mechanism which
establishes the handle size, as taken along line 3--3 of FIG.
2.
As perhaps best shown in FIG. 2, the luggage cart 10 of the present
invention is of the generally known type comprised of an upright
handle frame 12 and a foldable platform section 14 upon which
luggage or packages 16 can be transported.
Handle frame 12 includes a horizontal handle 18 consisting of a
rubber or plastic covering formed about a hollow metal tubing 20
which has two dependent legs 22 that are sized to telescope easily
within a cooperating pair of lower two vertical members 24 of frame
12. At the lower end of tubing members 24 a rodlike cross member 26
is fastened to form an axle for the wheels 28 which are connected
thereon in a conventional manner. An additional cross member 30,
welded to vertical members 24, has its outboard end shaped in a
loop form over wheels 28. This loop form is intended to support any
"soft" luggage on platform 14 that might otherwise rub on wheels
28.
In a preferred embodiment, another cross member 34, anchored at the
lower ends of members 24, is used as a pivot for the main "U"
shaped member 36 of platform 14.
As best shown in FIGS. 1 and 2, a support leg 38 is pivotably
mounted in member 36 and is braced by a pair of link members 40.
Leg member 38 has a horizontal cross piece joined near its upper
end. The ends of links 40 are pivotable about axle 26 and cross
piece 42. Links 40, axle 26 and cross piece 42 are located and
dimensioned as to cause leg 38 to be extended from "U" member 36
when cart 10 is in its FIG. 2 unfolded condition, and retracted in
the cart FIG. 1 folded condition. It is also to be noted that cross
member 30 serves as a stop for the inboard ends 44 of "U" member 36
as it rotates about rod 34 in the unfolded cart condition. What has
been described thus far are conventional structural features of
luggage carts. What will not be described are noteworthy
improvements according to the present invention.
Intermediate each cooperating pair of an upper handle leg or member
22 and a lower frame member 24 is a lock knob assembly 52 shown in
cross section in FIG. 3. The lower end of leg 22 is flared at 48 to
an outside diameter almost equal to the inside diameter of the
hollow lower frame member 24. Thus, when handle 18 is in its fully
extended or upwardly withdrawn position of movement, the flare 48
functions as a stop against an annular crimp 50 that is embodied in
the upper end of member 24, thus preventing total disconnecting
withdrawal of handle member 20,22 from handle member 24.
When the user wants to lock the handle 18 at a size anywhere
between fully retracted or collapsed (FIG. 1) and fully withdrawn
or extended (FIG. 2), he/she can do so by turning knob 52 which
causes threaded shank 54 to lock against leg 22. Shank 54 is fitted
to threadably engage a corresponding threaded throughbore of a hub
56 that is a molded structural feature of a cylindrical wall of a
cylindrical cap member 58 preferably made of hard rubber or
plastic. Frame member 24 has a traverse opening 64 in alignment
with the traversely oriented threaded bore of hub 56. Optionally,
opening 64 may be sized to be large enough to clear shank 54 or
alternately it may be slightly undersized as to be tapped as a
continuation of the internal thread of hub 56. Cap 58 is positioned
as a closure on frame member 24 and, to this end, the cap has an
inside diameter 60 that is press fitted on the upper end of a frame
member 24 and is provided with a throughbore 62 in its upper
surface that aligns with the upper opening of each hollow frame
member leg 24. Throughbore 62 is sized to allow sliding clearance
for each cooperating leg 22 and tubular member 24 receiving
same.
When both knobs 52, in both lock assemblies 46, are turned
counterclockwise, and thus to the "loose" condition, upper handle
18 can easily be raised or lowered to any desirable position. Knobs
52 can then be turned clockwise to the "lock" condition, to thereby
establish the overall size of the handle 18 which of course, is a
function of the extent that handle member 22 extends beyond the
upper openings of lower handle member 24.
In FIG. 3, the solid line drawing of leg 22 shows the leg in the
fully extended position and the phantom outline thereof is
illustrative of any intermediate position. The conventional or
prior art threaded interengagement of shank 54 in the threaded
opening 64 of the frame tubes 24 has, in accordance with the
present invention, been supplemented by additional teeth in
threaded interengagement that is provided by each threaded bore of
each hub 56 of each lock assembly 46, so that in the locking
position the increased number of teeth obviate inadvertent movement
from the selected position of movement of the extensible handle 18
during use of the luggage cart 10.
While the particular improved luggage cart herein shown and
disclosed in detail is fully capable of attaining the objects and
providing the advantages hereinbefore stated, it is to be
understood that it is merely illustrative of the presently
preferred embodiment of the invention and that no limitations are
intended to the detail of construction or design herein shown other
than as defined in the appended claims.
* * * * *